3 ms·

Curious why actual dolphins didn't evolve to use it. I'd guess it's some combination of horizontal vs. vertical stroke only mattering in the top meter of depth,

Curious why actual dolphins didn't evolve to use it. I'd guess it's some combination of horizontal vs. vertical stroke only mattering in the top meter of depth, and issues besides raw swim efficiency.

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mannykannot 11y ago
One reason may be that cetaceans evolved from land mammals that had evolved spine-flexing in the vertical plane as part of a galloping gait.
- pmontra 11y ago
  I think this is it. They should change the blueprint of their body and rotate eyes and snorkel by 90°. A pretty major adjustment. This also means we could teach something about swimming to dolphins :-)
  - mrec 11y ago
    > A pretty major adjustment. True, although flounders manage a similar 90° rotation, including migrating one of their eyes to the opposite side of their head during their early life. https://en.wikipedia.org/wiki/Flounder#Eye_migration https://en.wikipedia.org/wiki/Flounder#Eye_migration
- tarikjn 11y ago
  One other reason is that cetaceans need to come back to the surface for breathing and so their movements are more vertical axis based than horizontal vs. fishes. Horizontal tail propulsion allow a faster pitch control for swimming creatures than vertical + horizontal fins.
- Tloewald 11y ago
  As far as I know, Dolphins cheerfully swim on their sides when they want to. The point is they don't break the surface except when they want/have to so it does them no good. Here's a video of a dolphin swimming in shallow water: http://m.youtube.com/watch?v=Wk0X9hbaTuU http://m.youtube.com/watch?v=Wk0X9hbaTuU
JustSomeNobody 11y ago
Indeed. Maybe most of their hunting ability relies on their intelligence and not speed so they didn't need to develop past their current abilities. Or maybe it has to do with their need to breath. It certainly would be interesting to find out.
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3 ms·

Curious why actual dolphins didn't evolve to use it. I'd guess it's some combination of horizontal vs. vertical stroke only mattering in the top meter of depth,

by abecedarius 11y ago

deleted 11y ago
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mannykannot 11y ago
One reason may be that cetaceans evolved from land mammals that had evolved spine-flexing in the vertical plane as part of a galloping gait.
- pmontra 11y ago
  I think this is it. They should change the blueprint of their body and rotate eyes and snorkel by 90°. A pretty major adjustment. This also means we could teach something about swimming to dolphins :-)
  - mrec 11y ago
    > A pretty major adjustment. True, although flounders manage a similar 90° rotation, including migrating one of their eyes to the opposite side of their head during their early life. https://en.wikipedia.org/wiki/Flounder#Eye_migration https://en.wikipedia.org/wiki/Flounder#Eye_migration
- tarikjn 11y ago
  One other reason is that cetaceans need to come back to the surface for breathing and so their movements are more vertical axis based than horizontal vs. fishes. Horizontal tail propulsion allow a faster pitch control for swimming creatures than vertical + horizontal fins.
- Tloewald 11y ago
  As far as I know, Dolphins cheerfully swim on their sides when they want to. The point is they don't break the surface except when they want/have to so it does them no good. Here's a video of a dolphin swimming in shallow water: http://m.youtube.com/watch?v=Wk0X9hbaTuU http://m.youtube.com/watch?v=Wk0X9hbaTuU
JustSomeNobody 11y ago
Indeed. Maybe most of their hunting ability relies on their intelligence and not speed so they didn't need to develop past their current abilities. Or maybe it has to do with their need to breath. It certainly would be interesting to find out.
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